The present invention is directed to an arrangement for optimized weighting of transmitted transformation coefficients in transformation coders for the purpose of minimizing convolution distortions.
It is often necessary in transformation coding of images to transmit only a sub-quantity of all transformation coefficients for the purpose of a further data reduction or for the purpose of observing a prescribed channel rate. For example, in video conference coders which are based on the principle of transformation coding, a buffer controller means can reduce the transmission rate by prescribing a number less than all of the transformation coefficients to be transmitted. See, for example, Hoelzlwimmer, et al. U.S. Pat. No. 4,672,441. "Method And Apparatus For Picture Data Reduction For Digital Video Signals". This restriction in the number of coefficients to be transmitted can lead to convolution distortions in the reconstructed signal at the output of the receiver, such distortions being visible in an especially disturbing fashion, particularly at the edges of the visible objects.
A method for resolving this problem has hitherto not been known from the prior art.